The present invention relates to a tracheal stoma valve or vent. Such valves are known, for example, from European patents EP-B-0 221 973 and EP-B-0 617 630.
In the tracheal stoma valve mentioned in the latter publication, the valve has a valve closing element, which closes the valve in response to an air displacement. This is occasioned by the patient to be able to direct the air through a shunt valve between the trachea and the esophagus, in order to maintain a certain speaking capacity. In addition, the valve mentioned has a so-called blow-off valve element which, during response to a particular pressure, opens on the tracheal side of the valve. Consequently, when coughing, one needs to take care that the blow-off valve element opens and the air and sputum can be expressed from the stoma. This function is important, since otherwise severe complications can occur if, for example, the secretion (sputum) reaches the lobe of the lung where it can lead to severe infections.
With the known valve the blow-off valve element has an opening which is closable by the first mentioned valve closing element. In this way, the air can be so redirected that it can be guided through the mentioned shunt valve.
If the patient wishes to speak, a portion of the air stream must thus serve during exhalation for activating the mentioned valve closing element, so that this can be brought into its closed position. In addition, the patient must activate the valve closing element in the speaking mode once per breath, so that after each inhalation, he/she can bring the valve closing element back into the closed position, in order to be able to direct the stream of air by the shunt valve.
Even though the known valve has considerable advantages in comparison to older valve constructions, activating the valve closing element each time during speaking mode is felt by the patient to be uncomfortable.
An object of the present invention therefore consists in increasing the comfort of the patient while safety remains constant. This object is accomplished by a tracheal stoma valve according to the present invention. Further refinements and embodiments are described below and in the dependent claims.
Accordingly, it is provided that the tracheal stoma valve has a valve housing in which a valve flap is pivotably mounted. This is pivotable, upon inhalation with an air stream of a predeterminable strength, into a position sealing off the open lumen of the valve housing and, upon exhalation with an air stream of predeterminable strength, is pivotable into a position at least partially clearing the open lumen again. Moreover, it has a bypass valve element, through which respiratory air can be inhaled when the valve flap is in the closed position, whereby the two first switching points of the valve flap between the sealing position and the position at least partially clearing the open lumen of the valve housing are pre-adjustable.
The valve of the invention thus closes with its valve flap in an intensified inhalation operation, whereas the valve according to the cited EP-B-0 671 630 closes with an intensified exhalation. In contrast, the valve of the invention must be opened again by an intensified exhalation pressure, which, however, is conducive to the safety aspect if during coughing, etc. an overpressure is built up in the trachea which must be reduced through the valve. Here, the valve flap of the tracheal stoma valve of the invention to this extent also assumes the function of the blow-off valve element in the valve of the previously mentioned publication.
By an intensified inhalation the patient switches the tracheal stoma valve into speaking mode. With the subsequent exhalation no air escapes from the valve through the stoma, but instead is guided through the shunt or through the appropriate shunt valve, after which it is available for forming sounds and articulation. If the patient wishes to continue to keep the valve in speaking mode, he/she can once again inhale through the bypass valve element without the valve flap having to be pivoted even on short term and for a short time into the position at least partially clearing the open lumen of the valve housing. After successful inhalation has taken place, air is then directed again past the stoma by the shunt valve.
In contrast to the valves according to the prior art, it is not necessary here with each breath to activate the valve closing element mentioned there in order to activate further inhalations. The bypass valve element, which for switching (namely for closing upon beginning to speak) needs only the motion of a relatively small and light valve disk, ensures this.
According to a particularly preferred embodiment, it is provided that at least two permanent magnets are arranged on the valve flap, such that the one permanent magnet forms, with a first metallic sliding valve arranged in the valve housing, a magnetic closure in the sealing position of the valve flap, and the second permanent magnet forms, with a second sliding valve arranged in the valve housing, a magnetic closure in the position of the valve flap at least partially clearing the open lumen of the valve housing. This embodiment offers a very comfortable possibility of adjusting the switching points of the valve flap already mentioned, in that the holding force of the magnetic closures can be increased or decreased by activation of the respective sliding valve, since the contact between the permanent magnet and metallic sliding valve, and consequently the appropriate holding force, is greater or smaller, depending on the position of the sliding valve, as already known per se from the prior art.
An especially preferred embodiment provides that the bypass valve element is constructed as a recoil valve integrated into the valve flap. The recoil valve must open independently during the inhalation process and correspondingly close during the exhalation process. The recoil valve can here be constructed as automatically closing, so that the patient practically needs to use hardly any force or hardly any partial air stream at all, in order to close the bypass valve during the exhalation process, to keep the entire tracheal stoma valve in speaking mode.
Particularly preferred is an embodiment in which the valve flap is eccentrically suspended in the valve housing, by which it is to be understood that the center of gravity of the valve flap lies below the longitudinal axis of the valve housing. In this way, it can be achieved that the surface of the valve flap effectively exposed to the respective air stream upon the respective inhalation or exhalation process can be most effectively actuated, in order to be able to generate the torque (around the center of gravity) required for the pivoting motion.
A catch or limit stop can be formed on the valve flap for restricting the pivoting motion, in order to keep the valve flap constantly in a defined position. If the valve flap has such a catch, it is particularly preferred to provide that the already-mentioned second permanent magnet with the construction of magnetic closures, which is provided for a magnetic closure in the position of the valve flap at least partially clearing the open lumen of the valve housing, is arranged at the end of the catch. The first permanent magnet, which corresponds with the other position of the valve flap, can then be embedded on a face edge of the valve flap.